This invention relates generally to the field of mailing machines, and more particularly to sealing an envelope that is being fed through a mailing machine.
Generally, an envelope transport on a mailing machine transports envelopes along a feed path so that various functions may be performed on the envelope at different locations along the feed path. For example, at one location along the feed path the envelope may be weighed, at another location the envelope may be sealed, and at a further location an indicium for postage may be applied to the envelope. Drive rollers and/or drive belts may be employed to contact the envelope to propel the envelope along the feed path.
An envelope sealing component that is conventionally included in a mailing machine includes a sealing nip formed by an upper sealer roller and a lower sealer roller. After the adhesive on the envelope flap is moistened, the envelope is transported so that the portion of the envelope that includes the flap is fed through the sealing nip. As the portion of the envelope that includes the flap is fed through the sealing nip, the upper sealer roller applies pressure to the face of the envelope, and the lower sealer roller applies pressure to the back of the envelope, including the flap, so that the envelope is sealed.
Each of the sealer rollers is mounted on a respective shaft. When the mailing machine and its envelope sealing component are constructed in an ideal manner, the two shafts are exactly parallel in their respective orientations, so that the two sealer rollers apply substantial pressure to the envelope throughout the locus of the gummed portion of envelope flap. However, design tolerances and/or errors in assembly of the mailing machine may result in the two shafts being misaligned such that the shafts are at an angle to each other. In that case, most or all of the pressure applied to the envelope by the sealing nip may be concentrated at a small portion of the length of the sealer rollers. As a result, some or all of the gummed portion of the envelope flap may not be firmly pressed against the back of the envelope, so that the envelope is not reliably sealed by the sealing nip.
Therefore, it would be advantageous to provide apparatus and methods that improve the reliability of an envelope sealing component of a mailing machine.
Accordingly, an improved apparatus and method for sealing an envelope is provided. The improved apparatus includes an upper roller and a lower roller positioned relative to the upper roller such that the upper and lower rollers form an envelope sealing nip. The improved apparatus further includes an upper shaft on which the upper roller is mounted and a lower shaft on which the lower roller is mounted. The improved apparatus also includes a mechanism associated with the lower shaft for adjusting an orientation of the lower shaft to match an orientation of the upper shaft.
For example, the adjusting mechanism may include a ski which has a pair of ski arms for mounting the lower shaft. Each of the arms may have a slot formed therein, with a respective end of the lower shaft received in each of the slots. The adjusting mechanism may further include a pair of biasing mechanisms, such as torsion springs, for upwardly biasing the respective ends of the lower shaft in an upward direction.
In another aspect, a device for processing envelopes includes a base and a feed mechanism mounted on the base for feeding envelopes along a feed path adjacent a registration wall. The feed mechanism includes an endless belt having a lower belt run that is adapted to contact and propel the envelopes along the feed path. The feed mechanism further includes a plurality of pressure rollers biased to contact a lower surface of the lower belt run. The feed mechanism also includes a plurality of backup rollers in contact with an upper surface of the lower belt run. The device for processing envelopes further includes an upper sealer roller mounted on a common shaft with one of the backup rollers for rotation with the one of the backup rollers. The device for processing envelopes also includes a support shaft that extends substantially horizontally from the registration wall toward the feed mechanism. Also included in the device for processing envelopes is a ski that is pivotally mounted on the support shaft. The ski has two arms extending upwardly substantially in parallel to each other. Each of the arms has a respective slot formed therein. Each of the slots has a generally vertical course. The device for processing envelopes further includes an idler shaft having a first end received in one of the slots and a second end received in the other one of the slots. The device for processing envelopes also includes a lower sealer roller mounted on the idler shaft and in contact with the upper sealer roller. Also included in the device for processing envelopes is a first torsion spring installed on the support shaft adjacent one of the arms and in contact with the first end of the idler shaft to bias the first end of the idler shaft in an upward direction. The device for processing envelopes further includes a second torsion spring installed on the support shaft adjacent the other one of the arms and in contact with the second end of the idler shaft to bias the second end of the idler shaft in an upward direction.
The courses of the slots may be substantially straight or curved.
In still another aspect, a method is provided for sealing an envelope. The method includes forming a nip constituted by an upper roller mounted on an upper shaft and a lower roller mounted on a lower shaft. The method further includes allowing an orientation of the lower shaft to be adjusted according to at least one of (a) an orientation of the upper shaft, and (b) a cross-sectional profile of an envelope fed through the nip. The method also includes transporting the envelope through the nip.
The allowing step may include allowing an end of the lower shaft to travel in a slot in which the end is received. The end of the lower shaft may be biased in an upward direction.
Therefore, it should now be apparent that the invention substantially achieves all the above aspects and advantages. Additional aspects and advantages of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. Various features and embodiments are further described in the following figures, description and claims.